1 Introduction

GNU Aspell is a spell checker designed to eventually replace Ispell. It
can either be used as a library or as an independent spell checker. Its
main feature is that it does a much better job of suggesting possible
replacements for a misspelled word than just about any other spell
checker out there for the English language. Unlike Ispell, Aspell can
also easily check documents in UTF-8 without having to use a special
dictionary. Aspell will also do its best to respect the current locale
setting. Other advantages over Ispell include support for using
multiple dictionaries at once and intelligently handling personal
dictionaries when more than one Aspell process is open at once.

1.1 Comparison to other spell checker engines

Aspell

Ispell

Netscape

Microsoft

4.0

Word 97

Open Source

x

x

Suggestion

88-98

54

55-70?

71

Intelligence

Personal part

x

x

x

of Suggestions

Alternate Dictionaries

x

x

?

?

International Support

x

x

?

?

The Suggestion Intelligence is based on a small test kernel of
misspelled/correct word pairs. Go to http://aspell.net/test
for more info and how you can help contribute to the test kernel. The
current scores for Aspell are 88 in fast mode, 93 in
normal mode, and 98 in bad spellers mode: for more
information about the various suggestion modes Notes on the Different Suggestion Modes.

If you have any other information you would like to add to this chart
please contact me at kevina@gnu.org.

1.1.1 Comparison to Ispell

1.1.1.1 Features that only Aspell has

Is an actual library that other programs can link to instead of
having to use it through a pipe.

Does a much better job of suggesting possible replacements for a
misspelled word than Ispell does or for that matter many other spell
checkers I have seen. If you know a spell checker that does a better
job please let me know.

Can learn from user’s misspellings.

Can easily check documents in UTF-8 without having to use a special
dictionary.

Has support for using multiple dictionaries at once.

Is multiprocess intelligent. When a personal dictionary (or
replacement list) is saved, it will now first update the list against
the dictionary on disk in case another process modified it.

Can share the memory used in the main word list between processes.

A better, more complete word list for the English language. Word
lists are provided for American, British, and Canadian spelling.
Special care has been taken to only include one spelling for each word
in any particular word list. The word list included in Ispell by
contrast only included support for American and British and also tends
to included multiple spellings for a word which can mask some spelling
errors.

1.1.1.2 Things that, currently, only Ispell has

Lower memory footprint

Ability to deal with arbitrary multi-character letters such as old
ASCII encodings of accented letters.